Military vehicles are sometimes required to carry and/or transport heavy load modules (in excess of one ton). The term "load module" is used herein to refer to a variety of different devices, e.g. a freight container, portable shelter, missile launcher unit, personnel compartment, communications module, fuel storage unit, ammunition carrier, etc.
The load module must be securely fastened to the vehicle bed surface to prevent damage to the load or to the vehicle. In a typical situation the load-fastener mechanism comprises a plural number of threaded studs projecting upwardly from the vehicle bed surface through holes in a lower wall of the load module; a nut is threaded onto the upper end of each stud to prevent the module from being lifted off the studs.
Since these load modules are relatively heavy they must usually be lifted on or off the vehicle by power mechanisms (e.g. crane or forklift), or by the cooperative efforts of several men. The lifting-lowering operations must be carried out so that the holes in the module lower wall are vertically aligned with the studs on the vehicle bed surface. This is sometimes difficult to accomplish, especially if the load module is extremely heavy or an awkward shape to control (manipulate).
The present invention is directed to a threaded stud construction having a cam-type guide means thereon. The guide means comprises a specially-formed nut (or cap) having a convergent (conical) surface that acts to center the module wall hole on the stud axis (while the load module is being lowered onto the vehicle bed surface). Use of the guide means lessens the time required to correctly align and fasten the module on the vehicle bed surface.
Objects of the invention are to provide a stud-type module fastener means wherein:
1. the module attachment holes are quickly and easily aligned with the studs,
2. the studs are prevented from breakage or bending during the module-attachment operation.
3. the studs have low-cost detachable guides thereon for centering the module attachment holes on the studs, and
4. the centering guides take up minimum space on the studs.